use og ping-check

Staffan.Ungsgard at Staffan.Ungsgard at
Tue Mar 17 11:57:56 UTC 2009

Does the ISC Dhcp server Windows Vista work together regarding to "ping" ?

This is a snippet from Microsoft regarding Windows Vista and ping: 

"After you assign or change an IP address on a Windows Vista-based computer, the system searches the network for a computer that is already using this IP address. If the search reveals no computer that is already using this IP address, the IP address is officially assigned to the Windows Vista-based computer. The problem that is described in the "Symptoms" section occurs if another computer sends a ping message to the new IP address before the system finishes the search process. The system was not designed to be pinged while it is searching for a new IP address. " 

Full info here:

Can the DHCP-server ping makes Vista nack the lease because it thinks someone else has the address ?

-- Staffan Ungsgard

Staffan Ungsgård 
Senior Architect

TeliaSonera AB
Broadband Services, Product Management, TV & Home Services
Vitsandsgatan 9
123 86 Farsta, Sweden

Mobile +46-70-232-8550, Phone +46-8-504-62485
Email: staffan.ungsgard at

-----Original Message-----
From: dhcp-users-bounces at [mailto:dhcp-users-bounces at] On Behalf Of Simon Hobson
Sent: den 17 mars 2009 11:51
To: Users of ISC DHCP
Subject: Re: use og ping-check


>                 I would like to know what is the significance of 
>ping-check in dhcpd.conf what would be the impact if if disable it on a 
>production network .

It's there as a safety net - the idea being to check that there isn't another device using the address before offering it. Given the number of systems that now default to ignoring ping requests, it's of limited value. Turning it off shouldn't have any significant impact, but you may have a slightly higher chance of an address clash if someone configures a device in your dynamic range.

Simon Hobson

Visit for books by acclaimed author Gladys Hobson. Novels - poetry - short stories - ideal as Christmas stocking fillers. Some available as e-books.
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